BACKGROUND: Bipolar disorder is a frequent cause of disability and healthcare costs. Variability in outcome leads to a large number of treatment failures, typically followed by a “trial-and-error” process of medication switches. Pharmacogenetic tests (PGT) could help clinicians identify the best treatment. The primary aim of this preliminary study was to evaluate if PGT could help clinicians to individuate a better therapy in terms of clinical improvement. Secondary, safety and tolerability improvement, due to possible therapy’s change consistent to PGT, have been evaluated monitoring any treatment-emergent adverse event.METHODS: These study reports the preliminary results of an observational study, dealing with 2 patients affected by Bipolar Disorder I-II, not stabilized by the therapy, recruited from the University Psychiatric Unit of ASST Sette Laghi in Varese and from the ASST Santi Paolo e Carlo Borromeo in Milan, undergoing the Neurofarmagen test (AB Biotics). Patients were assessed using the following scales: the Clinical Global Impression (CGI) scale, the Young Mania Rating Scale (YMRS), the Hamilton Depression Rating Scale (HDRS), and the Dosage Record and Treatment Emergent Symptom Scale (DOTES). Both patients were receiving a suboptimal treatment. In both cases treatment was modified following the Neurofarmagen Test’s results.RESULTS: At one and three months follow-up an improvement in both patients’ psychopathology and tolerability emerged (Case 1: at T0 CGI=5, YMRS=20, HDRS=11; at T1 CGI=3; YMRS=13, HDRS=8; at 3 months the scales’ scores decreased: CGI=2, YMRS=4, HDRS=7; Case 2: at T0 CGI=5, YMRS=14, HDRS=15; at T1 CGI=3, YMRS=10, HDRS=7; at T2 CGI=2, YMRS=6, HDRS=4).CONCLUSIONS: This paper describes only two cases undergone to PGT, and this small sample it is a clear limit, but it suggests an interesting point of view about the important role of pharmacogenomics to help clinicians towards precision and personalized medicine.